Heretofore there have been a number of different types of electromagnetic launchers with rails.
FIG. 12 schematically illustrates the general construction of a conventional electromagnetic railgun. The railgun includes a pair of rails 1 and 2 positioned parallel to and spaced apart from one another. Rails 1 and 2 form barrel 3 which includes breech end 4 and muzzle end 5. Armature 6 is sized so as to slide between rails 1 and 2. The armature 6 and the projectile 7 may be combined into one body, or may be the same body. Rails I and 2 are connected to a source of electrical power 8.
The next explanation will define the operation. When the armature 6 is in the barrel 3, current begins to flow between the rails and 2 through the armature 6. This current produces a magnetic field to the left of the armature. This magnetic field interacts with the current flowing through the armature via path 9, to create an electromagnetic force that causes the armature to accelerate to the right along barrel 3, and out of the muzzle end 5 of the railgun.
In another type of railgun, known as a plasma armature railgun, current flows along path 10 through a plasma created by the electric current between the rails to the left of an electrically insulating projectile 7 which is used in place of the armature 6. Current running through the plasma interacts with the magnetic field generated by the current in the rails and results in acceleration of the plasma, and therefore of the insulating projectile, to the right along barrel 3.
A primary objective of electromagnetic launcher design is to maximize efficiency by minimizing energy losses in the electromagnetic launcher system.
Some sources of energy loss in an electromagnetic launcher system are:
resistive losses in the rails and any supply conductors, loss in the plasma behind the projectile and/or in the armature of projectile PA1 loss of the energy due to the force of friction between the projectile and the walls of the barrel bore PA1 loss of energy stored in the magnetic field from the rail current, which is dissipated in muzzle resistors after each shot.
The present invention reduces the energy stored in the magnetic field from the rail current.
In U.S. Pat. No. 4,796,511 to Eyssa, the author makes an attempt to reduce these losses by segmentation of the rails and by special supply conductors (See FIG. 13). Both supply conductors 11 and 12 have two semi-cylindrical portions: 13 and 14 for supply conductor 11, and 15 and 16 for supply conductor 12, respectively.
The portions 13 and 14 are electrically connected with segmented rail 17 and the portions IS and 16 are electrically connected with segmented rail 18. These semi-cylindrical portions are disposed on either side of the projectile path between the rails and in generally coaxial relationship to one another.
The author supposes that because the semi-cylindrical portions are coaxially arranged the magnetic field from current in such portions will not exist inside of barrel.
Because the currents flow in opposite directions in nonsymmetrical coaxial supply conductors, the currents are repelled by one another and the density of current will be distributed as shown in FIG. 13. These currents will create a magnetic field 19 inside the barrel and the stored magnetic energy will be lost after each shot.